Incidence and prediction of psychiatric morbidity after a motor vehicle accident in Japan: the Tachikawa Cohort of Motor Vehicle Accident Study

Abstract

Objectives: To assess both the incidence of new-onset psychiatric illness after involvement in a motor vehicle accident in Japan for comparison with Western data and the predictors of psychiatric morbidity and posttraumatic stress disorder (PTSD) evaluated immediately after the accident.

Design: Prospective cohort study of injured patients assessed immediately and 4-6 wks after involvement in a motor vehicle accident.

Setting: Intensive care unit in a teaching hospital in Tokyo, Japan.

Patients: Total of 100 consecutive patients with motor vehicle accident-related injuries (mean Injury Severity Score, 11.2; mean Glasgow Coma Scale, 14.5; age, 18-69 yrs) admitted to the intensive care unit. Patients with traumatic brain injury, suicidality, current psychiatric or neurologic illness, or cognitive impairment were excluded.

Measurements: An extensive clinical interview and evaluation of vital signs, sociodemographic variables, previous traumatic events, family history of psychopathology, Impact of Event Scale-Revised, Hospital Anxiety and Depression Scale, Clinician-Administered PTSD Scale, and Mini-International Neuropsychiatric Interview.

Results: A total of 31 patients showed some form of new-onset psychiatric illness at the 4- to 6-wk follow-up. The majority of illnesses consisted of depression (major depression, n = 16; minor depression, n = 7) and PTSD (full PTSD, n = 8; partial PTSD, n = 16). Other illnesses included alcohol dependence (n = 3), obsessive-compulsive disorder (n = 2), agoraphobia (n = 2), and social phobia (n = 1). Both psychiatric morbidity and PTSD were predicted by a sense of life threat (odds ratio, 4.2 and 6.2, respectively), elevated heart rate (odds ratio, 1.6 and 1.7), and higher Impact of Event Scale-Revised intrusion subscale score (odds ratio, 1.1 and 1.1).

Conclusion: This study showed that psychopathology and PTSD after a motor vehicle accident in Japan is common and that the incidence is within the range of that in Western countries. A combination of a sense of life threat, heart rate, and Impact of Event Scale-Revised intrusion subscale allowed for significant prediction of psychiatric morbidity and PTSD.